Black-line stains on teeth is a well known phenomenon, which relates to black stains appearing on teeth, generally more prevalent near the gums and on the back teeth, though can appear on any teeth and may be distributed on the entire tooth, not only near the gums.
Though the cause for the black-line stains is not fully known, it is thought to be partially caused by dental plaque in the same manner as other topical stains on teeth are caused. Although, dental plaque is caused by bacteria, the type of bacteria that causes black-stains is probably different than that which causes other stains. It is thought that lactobacillus, which is a genus of Gram-positive, facultative anaerobic or microaerophilic bacteria, is the cause of the plaque on teeth that results in black line stain. Generally, black-line stains are more prevalent in children, though can appear in adults as well.
Gingival scrapings from the teeth of patients with black-line stains have been shown to contain high phosphate content as well as high calcium content. Further testing has shown an insoluble iron compound in the black-line stain. It is thought that the lactobacillus, or possibly other bacteria, and the insoluble iron compound may cause of black-line stain. Further, it is thought that the insoluble iron compound is formed due to the interaction of hydrogen sulfide produced by the bacteria and the iron in the saliva or gingival fluids.
Although the black-line stains are medically harmless, they are not esthetic. Further, the removal of black-line stains is difficult, and may be performed by scaling and polishing by a dentist or a dental hygienist. Additionally, once removed, the black-stains tend to recur, even if the patient takes all necessary oral hygiene measures.
Currently, there are no known formulations, mouthwashes, toothpastes, toothbrushes and the like for treating the black-line staining. Thus, there is a need in the art for such treatments.